Effect of Magnetic Field on Dry Sliding Friction Mechanism of 1Cr18Ni9Ti

Abstract

The dry friction mechanism of paramagnetic austenitic metals under a magnetic-field may be different from general paramagnetic alloys because their magnetic properties with obvious work-hardening characteristics are changed during the dry sliding friction. The 1Cr18Ni9Ti (paramagnetic) is selected as the subject investigated to conduct dry sliding friction test via applying different magnetic field strength. Combined with the results of microscopic instruments SEM, EDS, XRD analysis, the magnetic field dry friction mechanism was explored. The results show that, the working hardening characteristics of austenite 1Cr18Ni9Ti change its magnetic properties. The friction surface and the subsurface layer form the rheological layer, which improved the hardness and magnetic permeability of the friction superficial-layer. As magnetic-field exerted, debris caused by wear is adsorbed on the friction superficies, and partially retained by magnetic attraction action, which prevents the direct contact between the matrixes of the friction pairs. The abrasive debris is easy to be refined by grinding, and the magnetic field is favorable to oxidation. Under combined action of magnetic field and friction heat and oxygen in the air, the oxide layer is formed. And the adhesion and adsorption between the abrasive debris and the substrate are strengthened, so that the wear rate is reduced. In this paper, the work hardening phenomenon of 1Cr18Ni9Ti is analyzed and studied, and the dry sliding friction mechanism of friction pair (high speed steel-1Cr18Ni9Ti) under the interference of magnetic field is discussed, which provides reference and theoretical support for the study of magnetic field dry tribology of friction pair composed of ferromagnetic alloy material and paramagnetic alloy material, as well as the friction pair composed of alloy materials with different magnetic properties.